The present invention relates to metal molds for continuous casting of steel bands and having wide side and narrow side walls, with the wide side walls having a funnel-shaped pouring region that reduces the size of the cast band toward the narrow side walls and in the pouring direction, and with the narrow side walls extending parallel to each other and being adjustably arranged between the wide side walls.
A metal mold of this type is disclosed in European Publication EP-B1 0 149 734. In order to prevent jamming of castings as a result of mold contraction, the wide side walls of the mold are formed with parallel wall portions extending sidewise of the pouring region and space a distance corresponding to the band thickness. The parallel side wall portions extend up to respective narrow side walls.
Because of this shape, forming of a trapezium-shaped solid formation in the region of the inclined wide side wall is avoided, and formation of a shell structure in the parallel region does not lead to jamming.
By displacing the narrow side walls in the parallel region, it is possible to change the width of a casting during the casting process. If casting of a workpiece with a larger thickness is required, the narrow side walls need be changed.
Another type of a metal mold, a continuous metal mold, is described in German Patent DE 35 01 422 C2. This mold has wide side walls and narrow side walls that converge in the casting or metal flow direction. The converging wide side walls bulge outwardly so that they have a larger radius at the inlet end than at the outlet end. At their ends directed to the narrow side walls, the wide side walls have flat locating surfaces which are abutted by flat counter surfaces of the narrow side walls.
The shape of the walls of this mold enables changing of a casting thickness during the casting process. However, to this end, it is necessary to displace the narrow side walls vertically, i.e., in a direction opposite to the casting direction. Further, when this continuous casting mold is used, the wedge-like shape of the casting and extending from the inlet end to the outlet end, results in occurrence of undesirable deformations, in particular, in the border region.
Accordingly, the object of the invention is a metal mold which provides for changing the thickness of a casting in a closed mold and for extraction of the casting, without deforming the narrow side walls and/or the casting border region.